San Francisco is leading the way for a new generation of green cities, writes Nick Ryan.

It has been popularised in song, long-associated with the birth of the hippy movement and is said to have one of the largest gay populations in America.

From pictures of the Grateful Dead standing in Haight-Ashbury to the rainbow flags of The Castro, San Francisco on the west coast of the USA, in California, is about as "cool" and liberal a city as the visitor will find in North America.

Known to some as "San Fantastico", as well as "The Shaky City" (for its proximity to the San Andreas fault and a large earthquake which destroyed it in 1906), the streets of San Francisco are famed throughout the world for their steep hills, trolley cars and Hollywood car chases (with chassis-grinding jumps).

From the faded grandeur of Nob Hill to the crowded Japantown, at the foot of the stunning Twin Peaks to its two-dozen parks and the tourism of Fisherman's Wharf, San Francisco is a world of coffee shops and vying languages, boutiques and art galleries, and – on the days when it is sunny – stunning views over the Bay and the giant majesty of the Golden Gate Bridge, spanning northwards into California's wine country.

But it is also hoping to become one of the world's greenest cities.

Greening

In fact, in recent months the city authorities have banned plastic shopping bags, developed the largest urban compost programme in the U.S. and will boast a 100 percent eco-friendly taxi fleet by 2011.

The city has a 'green' map (with every possible green resource marked), a green business programme, 'green' corporations, green mini-mall, the nation's largest green festival, a green schools alliance, a $100m+ green grants and building programme to help promote greener, affordable, low-cost new homes and renovations, and a long-established non-profit body which acts as guardian of the city's 'lungs' – its numerous parks.

On the world stage too, San Francisco laid down its credentials back in June 2005, becoming the first U.S. venue for UN World Environment Day. During this environmental summit, Mayor Gavin Newsom signed Urban Environmental Accords that launched San Francisco’s Livable City initiative ("to make the city a world leader in city greening by 2010").

And the city's green credentials are rising with each year it seems. The Green Guide named it one of the top 10 green cities in the U.S., citing that it put transit first (it has extensive rail networks, trolley cars, buses and ferries) and dedicates over 17 percent of its 47 mile territory to parks and green space.

Meanwhile, the Readers Digest marked it as one of the top five cleanest cities in America, ranking it high for its air quality and scoring a perfect mark for clean water.

The list rolls on: number one running city, as judged by Runners World magazine; the most sustainable city according to SustainLane.com; and in March 2005 it was ranked among the top 10 best U.S. walking cities by the American Podiatric Medical Association.

By November 2006 San Francisco had become the first American metropolis to certify greenhouse emissions (GHG), earning the distinction of Climate Action Leader with the California Climate Action Registry.

Even the city's Christmas lights this year are energy-saving LED: the Pacific Gas and Electricity Company (PG&E) is sponsoring a major 'Let's Green This City' campaign and has donated thousands of the lights to the famous Macy's Holiday Tree in Union Square, outside Macy's, the world's largest department store.

Companies and city-based organisations are falling over themselves to make San Francisco a more palatable, and green, place in which to live and do business.

City-wide response

Right across the sometimes clammy city – which Bay area residents choose to flee northwards to summer houses in the summer months – more than 16,000 trees have been planted since 2004 (after the Mayor pledged that 25,000 trees would be planted at an average of 5,000 per year).

The Mayor has also pledged to make all taxis run on hybrid or alternative fuels by 2011 (all the refuse and recycling trucks now run on biodiesel or liquefied natural gas). Not only that, but the MUNI (Municipal Transport Agency) has said it will make its vehicles emission-free by 2020.

Furthermore, restaurants are now banned from using polystyrene foam containers, and earlier this year San Francisco became the first American city to ban plastic shopping bags. It already recycles just over two-thirds of its rubbish and the aim is to raise this to three-quarters by 2010 (and to 100 percent a decade after that).

It has also just been announced, in December 2007, that San Francisco is to launch the world's first city-based carbon offset fund, helping industry and consumers balance their impact on global warming (by creating a fund to bankroll initiatives to cut greenhouse gas emissions).

The directive is the latest in a series of environmental initiatives announced by the Mayor, including strict "green" standards for new construction, a "carbon tax" on businesses to encourage energy conservation, financial incentives for businesses and residents to install solar panels and a recycling programme to turn used grease and cooking oil from the city's restaurants into biodiesel.

On the more personal level, you can now take bike and walking tours of the fabulous Golden Gate Bridge, as well as follow a guide on a 'segway' (a two-wheeled, self-balancing electric bike) around the major landmarks of the port.

Corporations

In true San Franciscan style, even the corporations are just a tad bohemian: energy company PG&E is sponsoring artists to display "treasures" saved from the city's dumps in impromptu open-air cafes. Visitors are served fair-trade, organic coffee in mugs that can be taken home and reused, or recycled. Limited edition books are on hand to prompt discussion of the artworks.

Laughter aside, the company purchases biomethane produced from 'cow pats', delivering it from farmers to customers via a natural gas pipeline, a system which spans over 40,123 miles throughout the state.

Over 60 schools have been supplied with solar panels, too, under PG&E's 'Solar Schools Program' and the company has a commitment to produce 20 percent of its energy from renewable sources, (including nine solar-powered power plants out in the Mojave Desert) as well as launched a Hispanic advertising campaign to all its Spanish speaking residents.

So if you're looking for a green adventure this winter or spring, the shores of the world's most famous bay might just be the place to find them.

Top 5 Greenest Cities on Earth

Reykjavik, Iceland
"Greenland is icy and Iceland is green" – that saying is truer than ever thanks to progress made by Iceland and its capital city in recent years. Reykjavik has been putting hydrogen buses on its streets, and, like the rest of the country, its heat and electricity come entirely from renewable geothermal and water-powered sources. It is determined to become fossil-fuel-free by 2050. The mayor has pledged to make Reykjavik the cleanest city in Europe.

Portland, Oregon, U.S.
The City of Roses' approach to urban planning and outdoor spaces has often earned it a spot on lists of the greenest places to live. Portland is the first US city to enact a comprehensive plan to reduce CO2 emissions and has aggressively pushed green building initiatives. It also runs a comprehensive system of light rail, buses and bike lanes, to help keep cars off the roads, and it boasts 92,000 acres of green space and more than 74 miles of hiking, running, and biking trails.

Curitiba, Brazil
Its bus system us hailed as one of the world's best and with municipal parks kept trim by a flock of 30 sheep, this mid-sized Brazilian city has become a model for other metropolises. About three-quarters of its residents rely on public transport, and the city boasts over 580 square feet of green space per inhabitant. As a result, according to one survey, 99 percent of Curitibans are happy with their hometown.

Malmö, Sweden
Known for its extensive parks and green space, Sweden's third-largest city is a model of sustainable urban development. With the goal of making Malmö an "ekostaden" (eco-city), several neighborhoods have already been transformed using innovative design and are planning to become more socially, environmentally, and economically responsive.

Vancouver, Canada
Its dramatic perch between mountains and sea makes Vancouver a natural draw for nature lovers, and its green accomplishments are nothing to scoff at either. Drawing 90 percent of its power from renewable sources, British Columbia's biggest city has been a leader in hydroelectric power and is now charting a course to use wind, solar, wave, and tidal energy to significantly reduce fossil-fuel use. The metro area boasts 200 parks and over 18 miles of waterfront, and has developed a way-forward-thinking 100-year plan for sustainability.